Radio Frequency Identification (RFID) technology is an alternative technology to optical barcodes, featuring additional functionality including not requiring light or line of sight during reading. Such tags can therefore be embedded into products or key fobs and be read even when dirty or scratched. In addition, RFID tags can store much more information, allowing more data to be conveyed than an optical code. Several RFID initiatives have joined forces under a common umbrella, known as Near Field Communication (NFC). NFC standards are defined by the Near Field Communication Forum, Inc. (NFC-forum), and all references herein are to their standards as updated per 2012-08-15 and freely available at their website.
U.S. Pat. No. 8,045,961B2 discloses a method for logging in for a client application with authentication of user data once a first device receives user data from second mobile device using NFC. Login information can be displayed on a screen on the device. Transactions are signed using common methods such as password, public key or a centralized service such as RADIUS.